Question

VB用鼠标拖动无标题窗体代码

Private Declare Function ReleaseCapture Lib "user32" () As Long
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hWnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
Private Const WM_SYSCOMMAND = &H112
Private Const SC_MOVE = &HF010&
Private Const HTCAPTION = 2
Private Sub Command1_Click()
End
End Sub
Private Sub Form1_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
ReleaseCapture
ret& = SendMessage(Me.hWnd, WM_SYS, SC_MOVE + HTCAPTION, 0)
'WM_SYS向窗体发送一个窗体移动命令
'SC_MOVE + HTCAPION单击左键移动窗体
End Sub
'
'
'以上是完整代码，请问哪里错了。窗体、控件的所有属性都为默认

Answer 1

Private Declare Function ReleaseCapture Lib "user32" () As Long
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long

Private Const WM_SYSCOMMAND = &H112
Private Const SC_MOVE = &HF010&
Private Const WM_NCLBUTTONDOWN = &HA1
Private Const HTCAPTION = 2

Private Sub Command1_Click()
End
End Sub

Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
ReleaseCapture
SendMessage Me.hwnd, WM_SYSCOMMAND, SC_MOVE + HTCAPTION, 0
'SendMessage hwnd, WM_NCLBUTTONDOWN, HTCAPTION, 0&
'上述两种方法都能实现该功能。
End Sub

Answer 2

Private Declare Function SetWindowPos& Lib "user32" (ByVal hwnd As Long, _
ByVal hWndInsertAfter As Long, ByVal X As Long, ByVal Y As Long, _
ByVal cx As Long, ByVal cy As Long, ByVal wFlags As Long)

Private Declare Function ReleaseCapture Lib "user32" () As Long
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
Private Const HTCAPTION = 2
Private Const WM_NCLBUTTONDOWN = &HA1

Private Sub Form1_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
'拖动窗体
If Button = 1 Then
ReleaseCapture
SendMessage hwnd, WM_NCLBUTTONDOWN, HTCAPTION, 0&
End If
End Sub